Running can give some runners a kind of euphoria and a reduced sensitivity to pain. In some cases, it can even help them to forget about time. Some runners describe it as an intense, blissful and emotional experience similar to an orgasm. For some, it is peaceful while others feel a burst of energy. Still others have never experienced the phenomenon of a runner’s high.

When media outlets break news stories about runners who have the audacity to cheat while attempting to win a marathon, what is your first reaction? Outrage? Anger? Maybe you feel sympathetic? As a student of human behaviour, you might wonder,